Principles of Calf Rearing

Colostrum vs Wholemilk:

Colostrum contains twice as much dry matter, three times as many minerals and five times the amount of protein compared to whole milk.

Colostrum Feeding:

The cows placenta does not permit the transfer of maternal antibodies, therefore calves are born immune incompetent.

Calves gain passive immunity by the absorption of specific proteins (IgGs) from their mothers’ colostrum.

In the first 24 hours the calves gut wall is permeable to these IgGs. It is crucial to get colostrum into the calf

within two hours of being born to ensure it acts as a source of passive immunity

Calves that do not receive sufficient colostrum are at increased risk of developing scour and are 74 times

more likely to die within the first 21 days of life (Teagasc Calf Rearing Manual).

Early Nutrition – Rumen Development

Early calf nutrition is focused on developing the calfs immature rumen, taking the calf from digesting milk to

digesting concentrates and forage. The development of the rumen is dependent on the chemical end

products of bacterial fermentation from concentrates.

Most important is butyric acid which comes from starch digestion.

For this fermentation to take place the bacteria need water. Milk does not act as a water source. For rumen

development it’s critical that the calf is fed a palatable concentrate made from cooked; flaked starchy raw

materials; a roughage source and clean water. Allow calves access to fresh concentrates, water and straw

from day 3.

Straw NOT Hay

Calves should be fed straw as opposed to hay. High intakes of hay can decrease concentrate intake,

limiting butyric acid production, and lead to the calves developing “hay/pot bellies”. The level of straw

required will depend on the physical structure of the concentrate, with finely ground rations needing more.

Successful rearing of your calves requires proper colostrum management and unrestricted access to:

– Clean water (in addition to milk/milk replacer fed)

– Fresh, palatable starter concentrate (preferably coarse)

– Straw

Allow access to fresh water, straw and Prime Elite Rumi Starter Pencils or Muesli from day 3